What is a kitchen extension?

A kitchen extension is an extension designed around a new kitchen, usually an open-plan kitchen, dining and family space at the back of the house. We build the extension and fit the kitchen as one project, so plumbing, electrics and lighting are planned around the layout from the start.
How much does a kitchen extension cost in High Wycombe?
In High Wycombe, a kitchen extension typically costs £2,500–£3,800 per m² including a mid-range kitchen, including VAT at 20% (standard rate). For a typical 22 m² project that is roughly £55,000–£83,500. Prices across the South East are typically 12% above the UK average for this kind of work, which is reflected in the range for High Wycombe. Design, structural calculations and council fees are extra.
| Size or type | Guide range |
|---|---|
| Smaller project (15 m²) | £37,500–£57,000 |
| Typical project (22 m²) | £55,000–£83,500 |
| Larger project (31 m²) | £77,500–£118,000 |
| Rate per m² | £2,500–£3,800 |
Your quote will depend mainly on:
- Extension size and roof design
- Who supplies the kitchen
- Island with sink or hob, which needs services in the floor
- Kitchen units, worktops and appliances
Use the guide price tool to see how size and specification change the figure, then ask for a written, itemised quote.
Do you need planning permission for a kitchen extension in High Wycombe?
Approvals for a kitchen extension in High Wycombe follow the rules for England. In England a single-storey rear extension is often permitted development: broadly up to 3 metres deep on a semi-detached or terraced house and 4 metres on a detached house, no higher than 4 metres, with eaves no higher than 3 metres within 2 metres of a boundary, and covering no more than half the garden. The larger home extension scheme allows up to 6 or 8 metres if you notify the council first and neighbours have a chance to comment. In conservation areas, National Parks and National Landscapes the larger home extension route, side extensions and cladding are not permitted development. Flats and houses whose rights have been removed need a planning application, and listed buildings need listed building consent.
Building regulations approval comes from the council’s building control service or a registered building control approver. The work is inspected at key stages, such as foundations, drainage and insulation, and a completion certificate is issued at the end.
We check this for your address before design work starts, so there are no surprises later.
What we handle
From survey to sign-off, the job normally involves:
- Electrics, lighting plan and sockets
- Extension structure, roof and glazing
- Kitchen fitting, worktops and splashbacks
- Drainage and water supply positioned for the sink and appliances
- Flooring and decoration
- Extraction ducted to outside
How long does it take?
The build itself usually takes 11 to 16 weeks on site, including kitchen fitting. Allow time beforehand for drawings and approvals, usually 6 to 12 weeks.
Building in High Wycombe
The South East has a broad mix of housing, from Victorian terraces in the towns to post-war semis and newer estates, so extension types vary street by street.
High Wycombe sits in Buckinghamshire, about 13 miles south of Aylesbury. We cover the whole of High Wycombe, including postcodes HP13.
How it works
- 01
Free visit
We look at the property, talk through what you want and measure up. There is no charge and no obligation.
- 02
Design and pricing
Design options, then a fixed quote based on the chosen drawings and specification.
- 03
Approvals in place
We handle planning, building control and neighbour notices before work starts.
- 04
Build and handover
Work follows the agreed programme, with inspections along the way and a completion certificate at the end.
Questions about kitchen extensions in High Wycombe
Should the kitchen be designed before the extension?
Yes. Knowing where the sink, hob and island will go lets us place drains, ducting, sockets and windows correctly during the build.
How long will I be without a kitchen?
Usually 3 to 6 weeks at the end of the job, once the back wall is opened and the new kitchen goes in. We can help set up a temporary kitchen.
Can I buy my own kitchen?
Yes. You can supply it and we fit it, or we supply it as part of the price. Either way we coordinate deliveries with the build programme.
Who approves a kitchen extension in High Wycombe?
Planning matters in High Wycombe go to the council covering your address, and the work needs building control approval. We prepare and submit the applications for you.
How much does a kitchen extension cost in High Wycombe?
In High Wycombe, a kitchen extension typically costs £2,500–£3,800 per m² including a mid-range kitchen, including VAT at 20% (standard rate). A typical 22 m² project comes to roughly £55,000–£83,500. Your fixed price depends on the survey and drawings.
